Concentrating Solar Thermal Power: Clean Energy for the United States

In the Southwest United States, an enormous solar energy resource remains largely untapped. There is already more than 500 MW of concentrating solar thermal power in the United States and Spain primarily, but there is significant scope to scale up development. As Congress oversees the nation’s transition to a clean energy economy, a homegrown renewable energy technology---concentrating solar thermal power---can help cut emissions and enhance energy security with American resources.

Concentrating solar thermal (CST)
technology uses reflective material
to concentrate the sun’s rays to
power steam turbines or engines.
When combined with thermal energy
storage—which enables a plant to produce
power under cloud cover and after the sun
has set—CST can generate electricity on
demand, not just when the sun is shining.
This makes CST different from many other
renewable power sources. While many renewables
provide power intermittently, CST
with thermal energy storage can provide
around-the-clock power, potentially offering
a low-carbon solution to baseload power
demand.

CST, which can provide power without
increasing carbon dioxide emissions, will
be an important part of the energy solution
in the United States. Congress can enact
legislation that will facilitate bringing it to
scale. Below are specific recommendations
for how Congress can help the country take
advantage of CST:

Enact a price on carbon. CST currently
is more expensive than coal and
other fossil fuel sources. Because CST
is a low-carbon technology, enacting a
carbon price would help the technology
compete with conventional sources. Capand-
trade is one mechanism for developing
a carbon price.

Fund RD&D. Research, development,
and demonstration support will facilitate
cost reductions of materials and systems,
including thermal energy storage,
which can bring down costs to make CST
competitive with conventional sources of
baseload power.

Create a national Renewable Energy
Standard (RES). Currently, some states
with RES have a solar “carve out,” or a
percentage set aside that must come
specifically from solar. These policies
have accelerated deployment of CST
in those states and increased utility
confidence in the technology. A national
RES, including a mandate for solar,
would send a market signal to invest in
renewables such as CST.

Push for CST in international technology
partnerships. China, India, and countries
in the Middle East and North Africa have
great potential for CST. As a promising
option to reduce GHG emissions and
improve energy security, CST should be
a priority in international collaboration
on RD&D issues. For instance, the World
Bank’s Clean Technology Fund includes a
program dedicated to deploying concentrating
solar thermal power.

Concentrating Solar Power Prospects in the Southwest United StatesSource: NREL

Improve the grid and transmission
system. Greater federal oversight of the
electricity grid and/or improved coordination
between grid operators will help
bring CST power from the country’s prime
CST areas, the Southwest to a broader area.

Consider alternative investment incentives.
While tax credits such as the 2008
Investment Tax Credit extension are
important, they are subject to periodic
and uncertain renewal, which presents
a challenge to investors. Moreover, in
the current economy, tax-based incentives
may not be as accessible to project
developers as they have been in the past.
Incentives such as feed-in tariffs, widely
used in Europe, require utilities to pay
renewable energy generators a fixed,
above-wholesale price for the power they
produce. Thus, feed-in tariffs directly
raise the price paid for renewable generation
and guarantees it a buyer over a
period of time---a more stable signal to
investors.